1. Field
Apparatuses and methods consistent with exemplary embodiments relate to transmitting and receiving information data commonly provided to a fixed device and a mobile device.
2. Description of the Related Art
Existing terrestrial broadcasting physical standard groups (e.g. digital video broadcasting (DVB) or advanced television system committee (ATSC)) are directed to broadcasting a variety of services to fixed devices (e.g. smart televisions (TVs) or set top boxes in home) or mobile devices (e.g. smart phones).
With development of mobile networks and supply expansion of mobile devices, the need for enhancing terrestrial broadcasting physical standards covering mobile broadcasting is rising. High definition (HD) content services which can be received only at TVs in home need to be received at mobile devices with development of network and display technologies.
In general, a channel environment for broadcasting to fixed devices is better than a channel environment for broadcasting to mobile devices. Since a quality of received service data is changed according to a location of a mobile device due to its mobility, and moving speed and a reception environment while the mobile device is moving are changed, channel distortion is more serious in a channel for the mobile device than in a channel for a fixed device.
Therefore, when service data is transmitted through the channel for the fixed device, a desired data quality is ensured through control of a parity data amount. In contrast, when service data is transmitted through the channel for the mobile device, it is an effective way to overcome the serious channel distortion by obtaining a time diversity by interleaving forward error correction (FEC) words.
Since the Fixed and Mobile Common Service (FAMCOS) considers service data reception at both fixed devices and mobile devices, channel environments for both types of device have to be considered when service data for the FAMCOS is to be encoded and transmitted. When service data is FEC-coded considering a relatively inferior channel environment for mobile devices, mobile devices as well as fixed devices may receive a desired quality of service data.
However, as described above, since the channel distortion is serious in the channel environment for mobile devices, interleaving with a long duration has to be performed while such interleaving with a long duration is not necessary for the channel environment for fixed devices.
Therefore, a delay by a long duration for the channel environment for mobile devices is considered when both types of device are used. However, such delay is unnecessary when only the channel environment for fixed devices is considered. That is, since fixed devices are situated in the channel environment relatively better than mobile devices, the same delay required in the channel environment for mobile devices is not necessary in serving for the channel environment for fixed devices, and a delay smaller than that required in the channel environment for mobile devices may be sufficient.
Thus, there is a need for a method for simultaneously obtaining a small delay and a time diversity gain by simultaneously considering fixed devices and mobile devices.